I have used it and I like it... but to be honest it is just like most other diffusion products out there.. Omnibounce, etc.

It is a bit bulky so doesn't fit in my bag so carrying it while not attached to the camera/flash can be a pain and people do tend to ask me what is that "thing" in top of the camera.... a "plastic bottle"?

I just got one last week. Used at a wedding on the weekend. Over all it worked very well. You do have to adjust your flash setting to compensated for the reduced amount of light. In the portrait mode you will still get some shadow effect if you are to close to a back ground. However it is very reduced comparied to the standard flash. If you are not using a bracket it will help with the shadow effect. It has become another tool in my bag. The only problem is that it is large and takes up room in my bag. Overall I my wife and I both like the results.